Effect of selected factors on total carotenoid content in potato tubers (Solanum tuberosum L.)

In the years 2004 and 2005 precise field trials were performed with the aim to evaluate the effect of variety year of cultivation, N, P, K and Mg fertilization, and the cover with white propylene fibre Paegas-Agro UV 17 on the total carotenoid content (TC) in potato tubers. TC was determined by absorption UV-VIS spectrophotometry and obtained results were statistically evaluated (ANOVA and MANOVA variance analyses, Scheffe's test). Statistically significant differences (P = 0.05) in the ability of varieties to synthesize carotenoids were found (Karin, Agria and Marabel with high TC x Impala and Saturna with low TC) and also the year of cultivation significantly affected TC (5.8 mg/kg fw in 2004, 20.9 mg/kg fw in 2005). The effect of fertilization with N, P, K and Mg on TC in potatoes did not show any significant effect; however significant differences were observed among varieties. The effect of white polypropylene fibre in two early potato varieties (Adora and Impala) during three dates of harvest on TC in potato tubers was not significant. Contrariwise, statistically significant effects on TC were reported in the case of potato tubers maturity, year of cultivation and potato variety.